It is often desirable to clamp two work pieces together. For example, rectangular picture frames are made from four work pieces cut in a bevel at both ends, and the beveled ends of two work pieces fit together to form a frame corner. Each frame corner is held together by a fastener and or adhesive, and the frame corners must be clamped while the adhesive dries or the fastener is installed. Other situations involving clamping work pieces together include window frame assembly and furniture construction. With any of these examples, it is important to avoid work piece misalignment. Another consideration is proper clamping of corners having acute or obtuse angles. Many times the corner will form a 90° angle, as in a rectangular picture frame or window frame. But sometimes it is desirable to construct a frame with other angles. For example, some windows have octagon shapes where the work piece corners form obtuse angles. Therefore, it is desirable to provide a clamping device that can be used to firmly and accurately clamp work piece corners having a variety of angles.
Clamping corners are known in a wide range of structural designs. It is well known in the art that work piece corners can be clamped with rigid sleeves as taught by U.S. Pat. No. 4,527,784. These rigid sleeves slide over the work piece corner and clamp down on the top and bottom surfaces of the work pieces. These devices are unable to adapt to work piece corners having a variety of angles, however. Each rigid sleeve has a particular angle and will not fit onto work piece corners having a different angle. It is therefore desirable to provide a clamping corner that can adapt to work piece corners with varying angles.
Another design well known in the art is a clamping corner with pivotable pads as taught by U.S. Pat. No. 891,121. These clamps can adapt to work piece corners having angles other than 90° because they have pivotable pressure surfaces. These devices do not prevent the work piece corners from misaligning, however. The pivotable pressure surfaces are typically separated by a gap that allows the work pieces to shift relative to one another, thus misaligning the corner. It is therefore desirable to provide a clamping corner device that will prevent misalignment of the work piece corner.